Apparatus and process for separation and selective recomposition of ions

ABSTRACT

A device and process are disclosed for the separate removal of oppositely charged ions from electrolyte solutions and recombining them to form new chemical compositions. The invention provides the ability to create multiple ion flow channels and then form new chemical compositions therefrom. The process is accomplished by selectively combining oppositely charged ions of choice from different electrolyte solutions via the capacitive behavior of high electrical capacity electrodes confined in insulated containers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.61/455,516, filed Oct. 22, 2010, and U.S. Provisional Application No.61/572,413, filed Jul. 18, 2011, the disclosures of which areincorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to the selective re-combination of ionsfrom differing electrolyte solutions to provide a new manufacturingmethod for chemicals whose constituents are ions. This invention alsorelates to a novel process and apparatus for removal of ions fromliquids such as sea water, brackish water, and water with elevatedhardness.

BACKGROUND OF THE INVENTION

There are many useful chemical compounds which, given their limitedoccurrence in nature, are manufactured through chemical processes inwhich oppositely charged ions from one compound are exchanged for thoseof another. Because such processes typically involve a large number ofsteps to reach the final product, requiring formation of manyintermediate chemicals and also using a large amount of energy, there isa need for simplification of these processes and the reduction of energyconsumption for their manufacture.

Synthesis of such useful chemical compounds from chemicals containingthe constituent elements of these compounds is an ongoing goal ofresearch and development in the chemical industry. Known synthesisprocesses that have proven successful have been more direct and lessenergy intensive. One example is the Solvay process for manufacture ofsodium carbonate from sodium chloride (common salt) and calciumcarbonate (Lime Stone) using ammonia. The overall chemical equation forthe Solvay Process can be written as:

CaCO₃+2NaCl→Na₂CO₃+CaCl₂   (Equation 1)

However, in order to reach the end products, the Solvay process involvesmany intermediate steps, and is centered about a large hollow tower. Atthe bottom of the tower, calcium carbonate (limestone) is heated torelease carbon dioxide:

CaCO₃→CaO+CO₂

At the top of the tower, a concentrated solution of sodium chloride andammonia enter the tower. As the carbon dioxide bubbles up through it,sodium bicarbonate is precipitated according to the following equation:

NaCl+NH₃+CO₂+H₂O→NaHCO₃+NH₄Cl

The sodium bicarbonate is then converted to sodium carbonate by heatingit, releasing water and carbon dioxide:

2NaHCO₃→Na₂CO₃+H₂O+CO₂

Meanwhile, the ammonia is regenerated from the ammonium chloridebyproduct by treating it with the lime (calcium hydroxide) left overfrom carbon dioxide generation:

CaO+H₂O→Ca(OH)₂

Ca(OH)₂+2NH₄Cl→CaCl₂+2NH₃+2H₂O

Looking at Equation 1 above and comparing it to the many steps needed toaccomplish the Solvay Process, it is apparent that it would bebeneficial if the constituent ions of calcium carbonate and sodiumchloride can be independently isolated and recombined in a single step.

Another case in point is production of sodium hydroxide (NaOH) andhydrochloric acid (HCl) from common salt and water. The overall chemicalequation for this process is:

NaCl+H₂O→NaOH+HCl   (Equation 2)

However, this process involves the electrolysis of salt to generatesodium hydroxide and chlorine and hydrogen gases at great expenditure ofelectric energy followed by reaction of hydrogen and chlorine gases.However, if sodium and chlorine ions can be independently isolated, aswell as the constituent ions of water, then by mixing oppositely chargedions of the two input chemicals, the final products of sodium hydroxideand hydrochloric acid can be more quickly and easily generated.

The chemical equations above all adhere to the principal ofelectro-neutrality, which means that, in uncharged electrolyticsolutions, the concentrations of all ionic species are such that thesolution as a whole remains electrically neutral. That is, if oneremoves a certain amount of positively charged ions from an unchargedelectrolyte solution, the remaining negatively charged solution cannotregain its electric neutrality until the same amount of negative chargesare also removed, or until the balance of positively charged ions arereturned to the solution. Due to the great attractive forces generatedby positive and negative charge separation, the synthesis processes forvarious compounds have been based traditionally on phase shifttechniques, such as precipitation, evaporation or electrolytictechniques in which electric charge balance are constantly maintained.

The present invention has the goal of synthesizing new chemicalcompounds that traditionally have been hard to construct, by exchangingoppositely charged ions from one chemical compound for those of another.The invention also provides an innovative apparatus and method fordesalination of water by selective removal and depletion of ions.

Conventional desalination processes presently being used includedistillation, ion exchange, reverse osmosis, electro-dialysis andfiltering. Distillation is probably the oldest method of waterpurification. Water is first heated to boiling, and the water vaporrises to a condenser where cooling water lowers the temperature so thevapor is condensed, collected and stored. Most contaminants remainbehind in the liquid phase vessel. However, even modern distillationtechniques such as multi-stage flash distillation and multi-effectdistillation can be expensive, as they require large amounts of energyto evaporate the water and condense the fluid. Also, organics with lowboiling points cannot be removed efficiently from the distillate, andcan become concentrated in the product water.

Reverse Osmosis (RO) in recent years has been the preferred choice fornew desalination facilities, producing potable water by blocking thepassage of ions through the membranes used. However, the processrequires expensive membranes that must be meticulously maintained andreplaced at regular intervals, and high pressure and energy to pushsaline water through the very tight membranes.

Electro-dialysis (ED) is a combination of electrolysis and ion exchange,resulting in a process which effectively deionizes water while the ionexchange resins are continuously regenerated by the electric current inthe unit. This electrochemical regeneration replaces the chemicalregeneration of conventional ion exchange systems. In this method, twoelectrodes are positioned on the two sides of a stack of anion andcation exchange membranes, typically referred to as an electrolysiscell. The spacings between these membranes define compartments throughwhich water can flow. Saline water is made to flow through all thesecompartments while an electric field is established between the twoelectrodes. The outlets from every other compartment are connectedtogether. The stack is setup such that a cation exchange membrane facesthe cathode (negative electrode) and an anion exchange membrane facesthe anode (positive electrode). Movement of cations towards the cathodeand anions towards the anode causes the depletion of both ions fromevery other compartment referred to as dilute compartments and theirconcentration in the compartments between the dilute compartments calledconcentrated compartments.

As with RO, electrodialysis systems require feed pre-treatment to removespecies that coat, precipitate onto, or otherwise “foul” the surface ofthe ion exchange membranes. However, electrodialysis reversal canminimize scaling by periodically reversing the polarity of theelectrodes and/or the flows of the diluent and concentrate streams. Whenpolarity of the applied potential between the two electrodes isreversed, the dilute compartments become concentrated compartments andvice versa. This reversal process is used to clean and rejuvenate themembranes.

A great deal of innovative work has recently been done on ED technology.For example, published U.S. Patent App. No. 2011/0180477 to Ganzi et aldiscloses use of a pair of electrodialysis devices containingmonoselective membranes to partially desalinate the seawater beingtreated. The dilute stream from both devices are sent to an ion exchangesoftener where calcium and other scaling ions are removed or reduced inconcentration, and the effluent from the softener is sent to anelectrodeionization device to produce final water product. Despiteimprovements, ED technology still suffers from a number of shortcomings,such as high energy consumption and the need to pre-purify the incomingwater, such as with reverse osmosis.

Capacitive deionization (CDI) is an emerging electrochemical watertreatment technology that uses electrophoretic driving forces to achievedesalination. While CDI, like electrodialysis, drives ions to theelectrodes, CDI does not involve membranes. It is therefore a lowpressure process of deionization that has the possibility of directlycompeting with reverse osmosis or distillation as a means of deliveringwater free of ions at reduced cost and operating expense.

CDI works by sequestering ions or other charged species in theelectrical double layer of ultracapacitors. During CDI, ions areadsorbed or captured onto the surface of porous electrodes by applying alow voltage (1.0-1.7 VDC) electric field. The negative electrodesattract positively charged ions such as sodium, calcium, and magnesium;simultaneously, the positive electrodes attract negatively charged ionssuch as chloride, nitrate and sulfate. Unlike ion exchange processes, noadditional chemicals are required for regeneration of the electrosorbentin this system. Eliminating the electric field allows ions to desorbfrom the surface of the electrodes and regenerates the electrodes. Theamount of charge that can be collected is determined by the surface areaavailable on the electrodes.

There are a variety of CDI electrode materials and configurations toenhance performance. Optimized carbon aerogel is an ideal electrodematerial because of its high electrical conductivity, high specificsurface area, and controllable pore size distribution. In the chargingcycles of these capacitors, equal amounts of positively and negativelycharged ions are removed from the base electrolytic solutions (salinewater) and are attracted to the capacitor plates. Through many cycles ofpassage of a given volume of electrolyte solution between the capacitorplates, reduction in ion content is achieved.

CDI technology has received considerable attention due to its potentialfor lower energy consumption, and has been under continuous developmentsince the early 1970's. Even so, due to limitations in the amount ofions removed, and the time it takes to remove these ions, capacitivedeionization technology has been limited to low salinity waters anddeionization applications. Typical among earlier developments in thisfield are U.S. Pat. No. 5,425,858 to Farmer and U.S. Pat. No. 5,789,338to Kaschmitter. These patents exemplify the use of flow-throughcapacitors (meaning that saline water flows through the capacitor and inbetween capacitor plates) and developments in carbonaceous highcapacitance capacitor plate materials, respectively.

Most current CDI technologies use capacitor plate arrangements thatfollow various forms of parallel plate capacitors, as exemplified byU.S. Pat. No. 5,620,597 to Andelman. Further developments of higherelectrical capacitance and lower electrical resistance capacitor platematerials are exemplified by U.S. Pat. No. 5,626,977 to Mayer et al. andU.S. Pat. No. 7,505,250 to Cho et al. There have also been attempts atimproving the efficiency of the charging and discharging cycles byspecific electric circuitry as exemplified by U.S. Pat. No. 7,138,042 toTran et al.

While known desalination methods and devices may be useful for theirintended purposes, there currently is no device or method forsynthesizing new and useful chemical compounds from the byproducts ofdesalination. It would thus be beneficial to provide a desalinationdevice that can provide a means for creating new chemical compounds fromother chemical compounds containing their constituent elements. It wouldalso be beneficial to simplify the manufacture of various chemicalsubstances and to reduce the energy consumption for their manufacture.There is also a need for further improvement of ion separationtechnology by substantially increasing the amount of ions removed in anygiven time span.

SUMMARY OF THE INVENTION

Accordingly, the present invention generally relates to an apparatus andprocess for the separate removal of oppositely charged ions from each oftwo different electrolyte solutions as ion streams, and therecombination of these ion streams into new chemical compounds.Oppositely charged ions can be separately extracted from at least oneinput solution, resulting in depletion of ions from the input solutionand generation of two ionically imbalanced streams, i.e. a positiveionic stream and a negative ionic stream, each having an excess of onepolarity of ions. These ionic streams can then be drawn into an ion sinkand combined with ionic streams from a different electrolyte solution toobtain new solutions or chemical compounds as compared with the originalinput solutions.

A first aspect of the invention provides an apparatus for separation andselective recomposition of ions, comprising in combination: (a) a firstion repulsion cell through which a first electrolyte solution can pass,the first ion repulsion cell comprising an insulated container; (b) afirst electrode secured inside the first ion repulsion cell; (c) a firstpair of flow path means, one of the first pair of flow path meanshydraulically connecting the first ion repulsion cell to a first ionsink, the other of the first pair of flow path means hydraulicallyconnecting the first ion repulsion cell to a second ion sink, each ofthe first and second ion sinks comprising an insulated container madefrom nonconductive material and having a non-corrosive, metallicreference electrode secured inside, wherein each of the first pair offlow path means include a flow cutoff valve for selectively opening andclosing the flow path means and an ion selective membrane forselectively facilitating flow of ions from the first ion repulsion cellto the ion sinks while preventing the reverse flow of ions from the ionsinks to the first ion repulsion cell; (d) a second ion repulsion cellthrough which a second electrolyte solution can pass, the second ionrepulsion cell comprising an insulated container; (e) a second electrodesecured inside the second ion repulsion cell; (f) a second pair of flowpath means, one of the second pair of flow path means hydraulicallyconnecting the second ion repulsion cell to the first ion sink, theother of the second pair of flow path means hydraulically connecting thesecond ion repulsion cell to the second ion sink, wherein each of thesecond pair of flow path means include a flow cutoff valve forselectively opening and closing the flow path means and an ion selectivemembrane for selectively facilitating flow of ions from the second ionrepulsion cell to the ion sinks while preventing the reverse flow ofions from the ion sinks to the second ion repulsion cell; (g) anelectric current supply source for connecting to and controlling thepolarities of the first and second electrodes inside the first andsecond ion repulsion cells, wherein the electric current supply sourceis also connected to the reference electrodes inside the first andsecond ion sinks; and (h) a control device connected to the electriccurrent supply source and to each of the flow cutoff valves for sensingthe potential difference between the first and second electrodes insidethe first and second ion repulsion cells and then opening or closing theflow cutoff valves to allow ions to flow from the ion repulsion cells tothe ion sinks

A second aspect of the invention provides a process for the separationand selective recombination of oppositely charged ions from twodifferent electrolyte solutions, the process comprising: (a) providing afirst input electrolyte solution and a second input electrolyte solutionin insulated containers, each input electrolyte solution comprising anequal amount of positive and negative ions; (b) generating a positivelycharged ion stream and a negatively charged ion stream from eachelectrolyte solution; and (c) selectively combining the positive ionstream from the first input solution with the negative ion stream fromthe second input, and the negative ion stream from the first inputsolution with the positive ion stream from the second input solution, toform new chemical compositions.

A third aspect of the invention provides a process for generating ionstreams, comprising: (a) providing a first electrolyte solution and asecond electrolyte solution, wherein each solution is placed in aninsulated container and comprises an equal amount of positive ions andnegative ions; (b) separating the positive ions from the negative ionsin each of the first and second electrolyte solutions; (c) electricallydrawing the separated ions out of each of the first and second solutionsas positive and negative ion streams, wherein the ion streams aregenerated in a continuous fashion and each of the ion streams areselectively drawn through an ion selective membrane; and (d) poolingeach of the ion streams into either a first ion sink or a second ionsink.

The nature and advantages of the present invention will be more fullyappreciated from the following drawings, detailed description andclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate embodiments of the invention and,together with a general description of the invention given above, andthe detailed description given below, serve to explain the principles ofthe invention.

FIG. 1 illustrates one embodiment of the invention including two IonRepulsion Cells (IRC), two ion sinks and the command and controlinstruments.

FIG. 2 illustrates another embodiment of the invention having a singleion sink system.

FIG. 3 illustrates another embodiment of the invention in which one ofthe IRCs acts in a Redox mode.

FIG. 4 illustrates another embodiment of the invention in which two IRCsact in Redox mode.

FIG. 5 illustrates representative recorded data during various intervalsof test 1.

FIG. 6 illustrates representative recorded data during various intervalsof test 1.

FIG. 7 illustrates representative recorded data during various intervalsof test 1.

FIG. 8 illustrates variation of specific gravity of the diluted solutionas a function of time for test 1.

FIG. 9 illustrates representative data recorded during test 4.

FIG. 10 illustrates a single cell preferred embodiment of thisinvention.

FIG. 11 a illustrates a three-dimensional view of a stacked cellarrangement of one embodiment of the device of the invention.

FIG. 11 b presents a frontal view of the device of FIG. 11 a.

DETAILED DESCRIPTION OF THE INVENTION

This invention provides a process and apparatus for separating andremoving oppositely charged ions from a given electrolyte solution andthen selectively recombining these oppositely charged ion streams withion streams from a second electrolyte solution to form new chemicalcompositions. There are also variations in operational and designaspects of this invention in which the required ion streams can begenerated through Redox reactions.

As defined herein, the terms “ion” or “ions” refer to hydrated ions asthey exist in electrolyte solutions. The terms “active electrode” and“counter electrode” can also mean “anode” and “cathode,” depending ontheir charge. To explain the scientific basis of this invention, somebasics of capacitor science are reviewed and highlighted.

A conventional electric capacitor is an electric energy storage devicemade up of two electrically conductive plates that functions on thebasis of removal or placement of electrons from one conductive plate,resulting in the reverse phenomena of placement or removal of electronsfrom the other conductive plate of the capacitor, by the action of theelectric field generated by the charge removed or placed on the firstplate. This charge separation leads to a potential difference betweencapacitor plates and storage of electric energy by the capacitor. Theelectric potential, the electric charge and the electric energy storedin capacitors can then be used when capacitors are used in electriccircuits.

Capacitance (C) of a capacitor in units of Farad is defined as the ratioof the amount of charge (Q) in units of Coulomb placed on or removedfrom each of capacitor plates, to the potential difference (V) in unitsof Volts between capacitor plates, or:

C=Q/V   (Equation 3)

This electrical capacitance is a function of capacitor geometry andplate material and the permittivity of the material between the twocapacitor plates. Capacitance increases with larger plate sizes, smallerdistance between plates, higher permittivity of the material betweenplates and the use of higher surface area plate materials. In additionto the effect on increasing the permittivity, the choice of thedielectric material placed between the capacitors plates also set thelimit for the maximum potential difference between plates as it relatesto sparking which is electric discharging between capacitor plates orthe breakdown of the dielectric between the plates.

The amount of energy stored in a capacitor is directly proportional tothe amount of charge and the potential difference between plates. If theenergy stored in a capacitor is designated as (U) in units of Joule,then:

U=0.5*Q*V   (Equation 4)

The parameters and units are as defined earlier. Further it is notedthat when two capacitors with capacities “C1” and “C2” are placed inseries, the equivalent capacitance, or “Ceq” of the two connectedcapacitors, is defined by:

1/Ceq=1/C1+1/C2   (Equation 5)

This equation shows that when two capacitors are placed in series, theequivalent capacitance is effectively controlled by the capacitance ofthe capacitor with lower Capacitance. Further it is noted that as theamount of charge placed on two capacitors in series, herein denoted as“q” are equal, the potential difference between the plates of suchindividual capacitors denoted as “V1” and “V2” are defined as:

V1=q/C1   (Equation 6)

And

V2=q/C2   (Equation 7)

And therefore;

V1/V2=C2/C1   (Equation 8)

The total potential difference across the two capacitors connected inseries is herein denoted as V is:

V=V1+V2   (Equation 9)

The above equations and particularly Equation 8 clearly indicate thatwhen a capacitor with a very large capacitance in placed in series withanother capacitor with very small capacitance, most of the potentialdifference applied across the two capacitors will occur across thecapacitor with smaller Capacitance.

Since 1957 a new concept in capacitors has emerged. This new concept iswhat is typically referred to as super-capacitors or electrochemicalcapacitors or electric double-layer capacitors (EDLC) which all refer tothe same thing. In EDLCs the insulating dielectric is replaced with anelectrolyte and the plates are usually made up of high surface areamaterial incorporating such material as activated carbon, carbonaerogels or carbon aerogel composites. Carbon aerogels are electricallyconductive and porous material having a very large surface area and avery high electrical capacity. The capacitances of EDLCs are severalorders of magnitudes larger than regular capacitors that use metallicplates and insulating dielectrics.

The increase in the electric capacitance of EDLCs is thought to be theresult of formation of electric double layers, which are specificconcentration of ions on and at very close proximity to each of the highsurface area conductive capacitor plates. Thus, a charged EDLC includestwo internal capacitors placed in series. In each of these internalcapacitors, one capacitor plate is made up of a charged, conductive,high surface area plate and the other is made up of concentration ofions of opposite polarity in comparison to the charge on the highsurface area plate. The high capacitances of EDLCs are the result ofextremely small separation between the charged capacitor plates of theaforementioned internal capacitors.

Given the utility and level of control provided by the potentiostatdevice in implementation of the experiments, it is worth mentioning thata potentiostat is an electric current or potential supply source usuallyused to control three-electrode electrochemical cells. This devicefunctions by maintaining the potential of an active electrode at aconstant level with respect to a reference electrode by adjusting thecurrent at a counter electrode. That is, this device automaticallyapplies an opposing potential to the counter electrode such that thesame amount of ions of opposite polarity are generated at the counterelectrode to balance out the ions generated at the active electrode,allowing for maintenance of the intended potential difference betweenthe active and the reference electrodes.

The potentiostat device also allowed the specification of the currentsgenerated acting as a current source. This way, instead of specifying aset potential difference between the active and the reference electrode,the electric currents can and were specified and generated. As a result,the potentiostat automatically adjusted the potential difference betweenthe active and the reference electrodes on one hand, and the counterelectrode and the reference electrode on the other hand, so that thecurrents generated at both active and counter electrodes were equal inmagnitude and opposite in polarity. By the use of a potentiostat insteadof a more common potential or current source, the point of zeropotential can be specified. This point facilitated the execution andunderstanding of the tests. Indeed, in actual practice of thisinvention, simple potential or direct current power sources can replacea potentiostat as the electric fields generated that propagate and areestablished with the speed of light (300,000 km/second) are the same.That is, a direct current power source is capable of generating electriccurrents of opposite polarity, and it does not need to utilize thereference electrodes to equalize the currents at the active and counterelectrodes.

FIG. 1 illustrates an embodiment of the invention including two IonRepulsion Cells (IRCs), two ion sinks, and command and controlinstruments. A first IRC 1 is made of an insulated container 2 made fromnonconductive material, containing a first input electrolyte solution 3filled to a level 4 over a high capacity, high surface area,electrically conductive electrode 5 and has two flexible tubes or pipes6 and 7 connected to it. There is also a second IRC 21 with all theparts similar to IRC 1 and, designated with numerical identifiers thatare 20 digits higher than those of IRC 1, including a second inputelectrolyte solution 23. Each of the pipes 6, 7 and 26 and 27 areequipped with inline filter holders identified by numerals 8, 9 and 28and 29 respectively, each containing a membrane. Pipes 6 and 26 eachinclude a flow cutoff valve 31, and pipes 7 and 27 also each include aflow cutoff valve 32. IRCs 1 and 21 are hydraulically connected to ionsink 41 through pipes 6 and 26 and to ion sink 51 through pipes 7 and27. Ion sink 41 includes an insulated container 42, made fromnonconductive material, filled with electrolyte 43 to level 44 andhouses a non-corrosive metallic electrode 45 which is the referenceelectrode in this ion sink. Ion sink 51 is a duplicate of ion sink 41with all the parts identified with numerals 10 digits higher than thoseof ion sink 41. There is also an electric current supply source 60,illustrated here as a potentiostat 60 having electric ports 61, 62, 63,64 and 65.

In IRCs 1 and 21, electrodes 5 and 25 are preferably submerged belowlevels 4 and 24 respectively to avoid evaporation from exposed electrodesurfaces. Each electrode 5, 25 is connected to a non-corrosive metallicwire, 70, 71 leading out of the IRC. Reference electrodes 45, 55, of theion sinks 41, 51, are electrically connected to each other through wire72. Electric ports 61 and 62 of the potentiostat 60 are the activeelectrode and the counter electrode ports, respectively, and areconnected to electrodes 5 and 25 through wires 74 and 70 for IRC 1, andwires 71 and 75 for IRC 21. The potentiostat's active electrode sensingport 63 is also electrically connected to wire 70 through wire 76, andthe potentiostat's counter electrode sensing port 64 is electricallyconnected to wire 71 through wire 77. The connection between thepotentiostat's reference electrode port 65 to wire 72 (which connectsreference electrodes 45 and 55) is provided through wire 78.Potentiostat 60 also has another port 66 that outputs a voltage levelequal to the potential difference between the active electrode and thereference electrode ports 61 and 65. Cable 79 connects this port 66 toport 81 of control device 80. The four output ports shown in together asoutlet 82 of the control device 80 are each connected throughappropriate cables (not shown) to flow cutoff valves 31 and 32. Controldevice 80 senses the polarity of the potential difference between ports61 and 65 through port 66 and switches one set of flow cutoff valves 31or 32 open and simultaneously closes the other set.

Here it is noted that the membranes housed in the inline filter holders8, 28, 9 and 29 are single polarity ion exchange membranes, hereinreferred to as Ion Selective Membranes or ISM. When the system isoperated and the active electrode 5 is negatively charged and thereforethe counter electrode 25 is positively charged, one set of flow cutoffvalves 31 or 32 will have to be opened and the other set will have to beclosed. If under this condition the pair of flow cutoff valves 31 areopen through the action of the control device 80, the membrane in theinline filter holder 8 and 29 will have to be anion exchange membraneswhile the membranes in the filter holders 9 and 28 will have to becation exchange membranes.

With reference to FIG. 1, it can be appreciated that if the potentiostatpower supply source 60 is energized to any voltage level for the activeelectrode 5, and when the electrical insulation capabilities of theinsulated container 2 are high enough to prevent any exchange ofelectric charge between the contents of this container and the outsideenvironment except through electrode 5 and/or pipe 6 and 7, the build-upof potential of electrode 5 will lead to collection of ions of oppositepolarity with respect to the charge supplied to electrode 5 on and inclose proximity to this electrode. Consequently, and due to the chargeimbalance imposed on the electrolyte solution, ions of similar polarityas the charge placed on electrode 5 will now gather on and in closeproximity to the inner surface of insulated container 2, which is alsothe outer edge of the electrolyte solution 3 placed inside insulatedcontainer 2. Thus, if the polarity of the charge placed on the electrode5 is negative, that is, if electrons are moved onto electrode 5, thenions of positive polarity are attracted to this electrode from theelectrolyte and gather on and in close proximity to it, forming anelectric double layer. The imbalance in charge distribution in theelectrolyte solution 3 caused by attraction of some of its ions toelectrode 5 will result in repulsion of ions with opposite polarity withrespect to the ions attracted to electrode 5 and their collection at theouter edge of the electrolyte solution 3 which is the inner surface ofthe insulated container 2. This results in the formation of twocapacitors in series. One of these capacitors is formed betweenelectrode 5 and the ions residing or collected on and in close proximityto electrode 5, and the second capacitor is formed by the ions residingor collected on the inner surface of the insulated container anddistributed charges in the outside environment (ground). In the firstcapacitor the available surface area will be high and the chargeseparation will be extremely small, resulting in much higher capacitanceas compared to the second capacitor.

The amount of charge moved onto electrode 5 is governed by theequivalent capacitance of the two capacitors thus formed. In otherwords, if the capacitor formed by electrode 5 and ions collected on andin close proximity to this electrode is referred to as the innerinternal capacitor with a capacitance of “C1” and the capacitor formedby the ions collected on and in close proximity to the inner surface ofthe insulated container 2 and the outside environment is referred to asthe outer internal capacitor with capacitance of “C2” and as these twocapacitors are connected to each other in series through the electrolytebetween them, the equivalent capacitance of the system, “Ceq”, will beas defined by equation 5 (1/Ceq=1/C1+1/C2), and will therefore be verylow and close to the small value of “C2”. Furthermore, and based onequation 8 (V1/V2=C2/C1) and equation 9 (V=V1+V2), and also based on themajor difference between “C1” and “C2”, the majority of any potentialapplied to electrode 4 will be seated across the outer internalcapacitor with capacitance of “C2” and only a very small fraction of itwill be seated across the inner internal capacitor with capacitance of“C1”. In other words, there will be very little potential differencebetween electrode 5 and electrolyte solution 3.

As a numerical example, if electrode 5 is made up of carbonized aerogeland is placed in an electrolyte solution 3 in turn placed in aninsulated container 2, its capacitance and therefore that of the innerinternal capacitor can be assumed to be in the order of 10 Farads. Nowif the capacitance of the outer internal capacitor would be, asexpected, in the order of 0.2 micro-micro farads (μμF), the equivalentcapacitance of the hydro-electrochemical capacitor based on equation 5would for all practical purposes equal to 0.2 μμF. Therefore, if thepotential applied to the electrode 5 is 10 volts, and based on equation3 (C=Q/V) the charge that would move on to electrode 5 will be equal to2.0 E-12 coulombs. Now with reference to equation 6 (V1=q/C1) andequation 7 (V2=q/C2), and noting that the charge on both thesecapacitors will be equal, it becomes apparent that the potential seatedacross the 0.2 micro-micro Farad capacitor will be practically equal to10 volts and the potential seated across the 10 Farad capacitor will be2.0 E-13 Volts which is extremely small and practically negligible.

Based on the above and with reference to FIG. 1, when electrode 5 of IonRepulsion Cell (IRC) 1 is initially connected to pole 61 of thepotentiostat 60 and this power supply source is turned on while line 6and 7 are closed, the amount of charge transferred to the equivalentinternal capacitor will be governed by the equivalent capacitance andwill be very small. Yet, most of the potential applied will be seatedacross the outer internal capacitor.

But, if line 6 is opened with no membrane 8 holder and no flow cutoffvalve 31, then the liquid in pipe 6 connected to insulated container 2also forms a part of this outer internal capacitor and the potential atthe tip of this pipe located in insulated container 42 of ion sink 41will also have the potential of the outer internal capacitor withrespect to the outer environment or ground. By activating thepotentiostat and placing its reference electrode 45 in insulatedcontainer 42, the potential within the electrolyte in insulatedcontainer 42 will be at ground level. As a result the potentialdifference between the electrolyte in container 2 and the electrolyte incontainer 42 will be the source of flow of charges in pipe 6. However,given the fact that the electrolyte in line 6 contains both positivelyand negatively charged ions, continuous application of the electricfield established across this line will cause the flow of one polaritycharges in one direction and the flow of oppositely charged ones in theopposite direction. Thus, in order to allow for flow of excess chargesgathered on the outer internal capacitor to the outside through line 6,the use of Ion Selective Membranes becomes necessary. By the use of anISM of proper polarity, excess ions from container 2 move to container42, while the reverse flow of oppositely charged ions will be prevented.

Further, and with reference to FIG. 1, if the second IRC 21 is chargedby the use of a potentiostat device with charges of opposite polarity ascompared to IRC 1, the ions collected at the tip of pipe 26 will haveopposite polarity with respect to the charges collected at the tip ofpipe 6. Indeed, with the setup of the two devices 1 and 21 and with ISMof opposing polarity, and with proper function of the potentiostatresulting in equal magnitude ion currents generated in each of the IRCs,the excess oppositely charged ions from both IRCs 1 and 21 can bedirected to ion sink 41 and accumulate therein.

Once some charge is allowed to exit from the outer internal capacitor ofIRC 1 through line 6, almost the same amount of charge will now enterinto electrode 5 from the potentiostat. That is, as some charges leavethe outer internal capacitor, the behavior of the two connected innerinternal capacitor and outer internal capacitor will be as if thecapacitance of the outer internal capacitor has increased, resulting inthe increase of the capacitance of the equivalent capacitor andtherefore increase of charge in the inner internal capacitor. The otherconsequence of this charge transfer is the effect it will have on thepotential distribution between the inner and the outer internalcapacitors.

When some additional charge is moved into electrode 5, the potentialseated across the inner internal capacitor will increase according toequation 6. With the total potential applied across electrode 5 and theoutside environment being constant, the consequence is an equivalentreduction in the potential seated across the outer internal capacitorand a consequential proportional reduction in the charge in the outerinternal capacitor.

By continued transfer of charge from pipes 6 and 26 to ion sink 41, thepotential seated across the inner internal capacitors and their chargescontinue to increase. Once the potential seated across the electrode 5and liquid 3 reach the potential required for initiation of electrodereactions, potentially resulting in exchange of charge between the twoplates of the inner internal capacitor, further discharge of ions frompipe 6 may not cause proportional further increase in the potentialseated across the inner internal capacitor plates, and further electricenergy supplied by the potentiostat would no longer be stored. Undersuch conditions, Redox reactions are initiated. To prevent this event,at this stage the application of electric potential to electrodes 5 and25 can be stopped or alternatively, the polarity of the appliedpotentials can be reversed.

By dropping the potentials applied to electrodes 5 and 25 to zero, theions previously attracted to these electrodes will start to redistributein liquids 3 and 23 respectively, resulting in buildup of charge intheir respective outer internal capacitors. This potential build up andthe amount of charge transferred to the outer internal capacitors at theedges of liquids 3 and 23 will now lead to a new pattern of ion flow outof containers 2 and 22. In this discharging cycle, ions gathering at theouter internal capacitors in containers 3 and 23 will have oppositepolarity in comparison to the charging cycle. Here, instead of droppingthe potentials applied to electrodes 5 and 25 to zero, the appliedpotentials can be reversed, resulting in charging the inner internalcapacitors with reverse polarity. The effect in this case will be higherpotentials at the outer internal capacitors. At this stage the flowcutoff valves 31 on lines 6 and 26 can be closed and flow cutoff valves32 on lines 7 and 27 can be opened, leading to ion sink 51. With IonSelective Membrane (ISM) 9 allowing the passage of ions with oppositepolarity to those of ISM 8, and with ISM 29 allowing the passage of ionswith opposite polarity to those of ISM 28, there will now be anaccumulation of oppositely charged ion streams coming from each of theIRCs and passing into ion sink 51.

Thus, if the polarity of the charges placed on the electrode of a givenIRC (1 or 21) is positive, placement of a cation exchange membrane (ISM)in the line opened to connect a first IRC to the ion sink (which ismaintained at zero potential by the potentiostat) will lead to outflowof excess positively charged ions in the form of a positive ion streamfrom the first IRC to the ion sink. At the same time, the charge placedon the second IRC will be negative and should have an anion exchangemembrane on the line opened to connect it to the same ion sink, allowingnegatively charged ions to flow as a negative ion stream into the ionsink. At this stage, new chemical compounds can be formed in the ionsinks by selectively combining the positive ion stream from the firstIRC with the negative ion stream from the second IRC, and also combiningthe negative ion stream from the first IRC with the positive ion streamfrom the second IRC. Creation and selective recombination of ion streamsin this manner can be repeated until the extraction of ions from theinput electrolyte solutions leads to a desired level of depletion ofions from each of the electrolyte solutions, or until the collection ofnew chemicals reaches a desired concentration in the ion sinks. Poolingof ion streams into either the first ion sink 41 or the second ion sink51 is typically done by generating the ion streams in a continuousfashion from the input solutions.

Here it is also noted that if the polarity of the ion exchange membranes(ISMs) are such that they would not allow the excess charge collected atthe inner plate of the outer internal capacitor within a given IRC toflow out, and would instead only allow for passage of ions with oppositepolarity with respect to charges collected at the outer internalcapacitor, the effect will be that the excess potential of the innerplate of the outer internal capacitors will now be relieved by entranceof oppositely charged ions with respect to the charges collected atinner plate of the outer internal capacitor into this region fromoutside of the cell. Consequently, containers 2 and 22 will now act asion collection cells (ICCs) rather than ion repulsion cells (IRCs), andions will be depleted from containers 42 and 52 and will gather incontainers 2 and 22. Under this condition, ion sinks will now be ionsources. All other aspects including lowering of the potential at theouter internal capacitors and increase of potential difference betweenthe plates of the inner internal capacitor will be the same as thealternate case, detailed earlier.

With respect to FIG. 1 it is also noted that when the electrolytes inIRCs 1 and 21 are the same (e.g. sea water or brine) and the intent isdesalination, then there is no need to separate the ions leaving the twoIRCs and consequently there would be no need for the use of two ionsinks 41, 51 and they can be combined into one ion sink, as shown onFIG. 2. FIG. 2 illustrates nearly the same device as FIG. 1, except thatthe second ion sink is now eliminated and pipes 7 and 27, as well aspipes 6 and 26, all connect to ion sink 41.

Another embodiment of the present invention is beneficial when water(H₂O) is one of the electrolytes. For example, it is often desirable toproduce caustic soda (NaOH) and hydrochloric acid (HCl) from sodiumchloride (NaCl). For such cases, it is desired to split water moleculesinto positive H and negative OH ions. But, given the extremely lowelectrical conductivity of pure water, generation of large currents ofsuch ions in a capacitive mode would require the use of very largeelectric potentials. To resolve this issue, the modified process shownon FIG. 3 can be used.

In FIG. 3 all components identified by numerals up to the potentiostatoutput ports 82 are the same as those of FIG. 1, with the differencebeing that the second ion sink 51 and pipe 27 and its attached valve 32and ISM 29 are eliminated, and that electrode 25 now has much lowerelectrical capacitance compared to electrode 5. Obtaining a low electriccapacitance electrode can be easily achieved by using a metallicelectrode for electrode 25, while electrode 5 is still made out ofmaterial such as high capacitance carbons or carbon aerogels. In FIG. 3there is also pipe 90 that connects the empty space above liquid level24 to device 91. Further, pipe 7 no longer leads to the eliminated ionsink 51 and is instead also connected to device 91. There is also switch92 that can interrupt the flow of charge to electrode 25. Switch 92 isconnected to one of the output ports 82 of control device 80 throughconnections not shown. Here the input electrolyte solution 3 is a highconcentration solution of the raw material such as sodium chloride, andthe electrolyte 23 is a solution of specifically selected compoundtargeted to production of H+ or OH⁻ ions.

When the goal is for IRC 21 to generate OH⁻ ions, the electrolyte 23must contain cations that have lower electrode potential than H+ ions,such as sodium or lithium. By the use of electrolytes such as sodiumhydroxide (caustic soda), and with electrode 25 being connected to acathode, hydrogen gas (H₂) will emit from IRC 21 into the empty spaceabove it or to the outside of the cell, and OH⁻ ions will stream out ofline 26 when the ISM in filter holder 28 is an anion exchange membrane.Inversely, when the goal is for IRC 21 to generate H+ ions, theelectrolyte 23 would have to contain anions that have higher electrodepotential than OH⁻ such as sulfuric acid. Under these conditions, theelectrode 25 will be an anode (positively charged electrode), oxygen gas(O₂) will be emitted from IRC 21 to the empty space above it or to theoutside of the cell, and H+ ions will stream out of line 26 when the ISMin filter holder 28 is a cation exchange membrane.

Thus, looking at FIG. 3, when electrode 5 is positively charged, ISM 8is a cation exchange membrane allowing the passage of positive ions,valves 31 are open, ISM 28 is an anion exchange membrane allowing thepassage of negatively charged ions and valve 32 is closed, the operationof the potentiostat 60 will result in connection of a negative potentialto the now metallic electrode 25. With sufficient electric potentialapplied, electrode reactions (Redox reactions) are initiated atelectrode 25 facilitated by the contents of electrolyte 23. Ifelectrolyte solution 3 in container 2 is sodium chloride and electrolyte43 is to become a solution of caustic soda (NaOH), electrolyte 23 can bea solution of caustic soda too. Existence of a caustic soda solution aselectrolyte 23 in the vicinity of electrode 25 will now result ingeneration of hydrogen gas at this electrode, and IRC 21 will nowgenerate a negatively charged hydroxide (OH⁻) ion stream that will flowthrough line 26, accumulate in Ion sink 41, and neutralize thepositively charged sodium ion stream also entering container 42 fromline 6. This will result in the formation of NaOH in container 42. Hereit is also to be noted that if the requirements of a particular designdo not require the separation of the electrolytes 23 and 43, then valve31 on line 26 and its related ISM 28 can also be eliminated.

Once the potential difference between electrode 5 and electrolytesolution 3 reaches a level that can cause Redox reactions or at anyother convenient time before, the polarity of the potential applied toelectrode 5 can be reduced to zero (or can be reversed), the valves 31in lines 6 and 26 can be closed, and valve 32 opened. At this timeswitch 92 is also commanded to open state preventing flow of electricityto electrode 25. At this stage negatively charged chlorine ions flowingin line 7 can join the hydrogen gas flow in device 91. Device 91 is areactor in which hydrated chlorine ions and hydrogen gas can be combinedto form hydrochloric acid solution. It contains a platinum electrodeclosely spaced adjacent a proton exchange membrane. Hydrogen gas isallowed to flow between the electrode and the membrane. Chlorine ionsare directed to the electrolyte, filling the compartment behind themembrane. Hydrogen gas ionizes in contact with the electrode and passesthrough the membrane, combining with the chlorine ions and forminghydrochloric acid. The electrode in device 91 must be grounded throughan electrical lead so that the electrical energy generated can be used.Also, the grounded electrode reduces the potential of the electrode,allowing for further ionization of the hydrogen gas. Alternatively, thereactor device 91 can be an electrolysis half cell, generating oxygengas and a positively charged hydrated hydrogen ion stream, for combiningwith the hydrated chlorine ion stream flowing out of pipe 7, asdescribed with reference to FIG. 4.

The system presented on FIG. 3 can also be used without ionization ofhydrogen gas to produce the needed H+ ions. If needed, a system aspresented on FIG. 4 can alternatively be used. In FIG. 4 all parts aresimilar to FIG. 3 except that another cell 93 is included for Redoxreactions. Cell 93 includes an insulated container 94 filled with anelectrolyte 95 and is filled to level 96 and has a low capacity metallicelectrode 97, which is similar to electrode 25 (which in this case isalso metallic). There is also a diode bridge 98 at the connectionbetween wires 75 and 77 to wire 71. This diode bridge 98 is alsoconnected to wire 99 leading to electrode 97. Parts 93 to 99 on FIG. 4replace parts 90 to 92 of FIG. 3.

With reference to FIG. 4, when terminal 62 of power supply 60 ispositively charged and diode bridge 98 only allows the exit of electronsfrom electrode 25 (making it an anode), ISM 8 is a cation exchangemembrane allowing the passage of positive ions, valves 31 in lines 6 and26 are open, ISM 28 is an anion exchange membrane allowing the passageof negatively charged ions, and valves 32 in lines 7 and 27 are closed,the operation of the potentiostat 60 will result in connection of anegative potential to the now metallic electrode 25. With sufficientelectric potential applied, electrode reactions (Redox reactions) areinitiated at electrode 25 facilitated by the contents of electrolyte 23.If electrolyte solution 3 is sodium chloride and electrolyte 43 is tobecome a solution of caustic soda (NaOH), electrolyte 23 can be asolution of caustic soda too. Existence of a caustic soda solution aselectrolyte 23 in the vicinity of electrode 25 will now result ingeneration of hydrogen gas at this electrode, and IRC 21 will nowgenerate a negatively charged hydroxide (OH⁻) ion stream that will flowthrough line 26 and accumulate in Ion sink 41 and neutralize thepositively charged sodium ion stream also entering it from line 6. Thiswill result in the formation of caustic soda in container 42. At thisstage, if the polarity of terminal 62 changes, by the action of diodebridge 98, electrode 25 will be isolated and electrons begin to flowthrough wire 99 to the previously isolated electrode 97, making it acathode. If electrolyte 95 in container 94 is a solution such assulfuric acid, then the occurrence of electrode reactions at electrode97 will lead to generation of oxygen gas which can be released or put toother use. At this stage, if valves 32 in lines 7 and 27 are open whilevalves 31 in lines 6 and 26 are closed, if high capacity electrode 5becomes a cathode and electrolyte solution 3 is a sodium chloridesolution, and if ISM 9 is an anion exchange membrane and ISM 29 is acation exchange membrane, the H+ ions will stream out of pipe 27 fromcell 93 and neutralize negatively charged chlorine ions streaming out ofpipe 7. Although the energy use in the system of FIG. 4 is higher thanthe system of FIG. 3, there might be situations such as when the gasproduced from cell 93 is needed in other processes in which case thisoption can also be justified and put to use.

Because the present invention is based on absorption and release of ionsfrom capacitors, the rate of ion flow, which is equivalent to flow ofelectrons in regular capacitors, is a function of the Time Constant ofthe equivalent RC circuit. Since the time constant is defined ascapacitance (C) multiplied by resistance (R), the rate of ion transferwill be higher if the Time Constant is lower. Given this, along with thefact that capacitors are energy storing devices and that energyconsumption and dissipation in all RC circuits occur in resistiveelements, then it can be appreciated that the lower the electricalresistance in the system, the faster it can operate; and the lower itsenergy consumption for a given operating condition will be.

Further, the apparatus of the invention can function at differingprocess rates based on the applied potential. Looking at FIG. 1, it canbe appreciated that the rate of ion flow out of this system is not onlyprincipally controlled by the electric resistance of pipes 6, 26, 7 and27 (and their related attachments), but also by the developed potentialat the outer internal capacitor that acts on the ions within thesepassages. Thus, with the application of higher potentials to IRCelectrodes resulting in the development of higher potentials at theouter internal capacitor, higher process rates can be obtained throughthe same equipment. It is also noted that higher process rates result inhigher energy consumption.

A mathematical explanation of the above discussion is as follows:

Since power consumption Pr in any resistive element is defined asPr=V×I; and since electric current I is equal to the charge in unittime, t, it can be said that I=Q/t. As a result, Pr×t=Q×V. And since(Pr×t) is equal to the energy used, it is conclude that EnergyConsumption (in Jules)=Q×V. Thus, the resistive aspects of energyconsumption in this invention are dependent on the amount of charge andthe potential used. Given the fact that in utilization of this systemfor desalination or ion separation and remixing, the intent is totransfer a certain amount of charge, the higher potential used, thehigher the energy consumption and the faster the process rate.

Test Results

Test 1: This test was used to evaluate the transfer of ions from IRCs 1and 21 to the ion sinks 41 and 51 of FIG. 1. The electrolyte used was a1.02 specific gravity sodium chloride solution (Corresponding to a saltcontent of 2.7%) prepared by mixing commercially available distilledwater with laboratory grade sodium chloride described in the Equipmentand Materials section, below. The test targeted reduction of thespecific gravity of over 200 ml of input solution to 1.01 (correspondingto a salt content of 1.4%). As noted, the setup for this test used thearrangement presented in FIG. 1. In this test, individual IRCs were madeup of 1 and 3/16 inch OD transparent plastic tubes with the solutionheight of 170 millimeters. The electrodes in the IRCs were ⅜ in diametersolid carbon rods. The ion sink containers were ¾ inch in diametertransparent plastic tubing, also with a solution height of 170millimeters and were equipped with electrodes that were electricallyconnected to each other as well as to the reference port of thepotentiostat. Each IRC was hydraulically connected to the ion sinksusing total of 16 centimeters long natural rubber tubing with OD of 12mm. The filter holders and flow cutoff valves are described below in the“Equipment and Materials” section. The position of ISMs were chosen suchthat when negative voltage was applied to IRC 1, the negatively chargedions generated would flow through an anion exchange membrane and reachone of the ion sinks, while at the same time the counter electrode waspositively charged and caused positive ions to pass through a cationexchange membrane to the same ion sink. During this process the flowcutoff valves on both of these lines connecting IRC 1 and IRC 21 to thesame ion sink were open, and the other set was closed.

The power supplies used was a Gamry Reference 3000, controlled andoperated through a Sony VAIO laptop computer. Operation of the devicewas carried out through execution of input commands, organized inrepeatable input files. Gamry Reference 3000 potentiostat records theresults of the experiments which are stored in output files that couldbe used to plot out the results. In this test the maximum voltage ofpositive (+) 6.5 volts was applied for 100 seconds, followed by negative(−) 6.5 volts for 100 seconds in the potentiostat's Chronoamperometrymode, repeated for 20 cycles and covering 4000 seconds in each input andoutput file. This sequence was repeated for over 220 times over an 11day period (for effective period of approximately 244 hours) resultingin 4400 cycles of voltage reversals. During this time the test wasrunning for 216 hours. The remainder of the time, about 28 hours, wasmade up of a number of unforeseen shutdowns caused by auto hibernationof the controlling laptop (one 10 hours period) and the rest wasdistributed rather evenly throughout the period of testing for specificgravity measurements of the diluted and the concentrated solutions, andfor the following adjustments:

As noted, the electrodes used were ⅜ in diameter solid carbon rods. Atthe beginning of the test, they extended well above the liquid levels inthe IRCs and in the ion sinks In time it was observed that capillaryrise of the solutions in the electrodes was causing a drop in the liquidlevels as well as some precipitation of salt on the body of the of theelectrodes above liquid levels. In the early afternoon of the 3^(rd) daythe electrodes in the IRCs were shortened to just below the liquidlevels and were reconnected to the potentiostat through titanium wiresfirmly wrapped around each one. At this time the ion sink electrodeswere also changed to titanium wires. The liquid levels in the IRCs werethen refilled by one to two millimeters by similar solution as theoriginal input solution.

The liquid contents of the ion sinks were changed a total of 5 timesthroughout the test, with base solution of specific gravity equal 1.02.Typically this was done when the specific gravity of the concentratedsolutions approached or was higher than 1.024. From the beginning of thetest and up to the afternoon of the eighth day, the valve control systemwas operating with a delay of 5 to 10 seconds. This was corrected andthe continuation of the test was carried out with perfectly synchronizedvalve operations. This is clearly observable by comparison of FIGS. 5, 6and 7. Three output files from the total of over 240 files generated arepresented as FIGS. 5, 6 and 7 distributed throughout the testing period.

FIG. 8 shows the variation of specific gravity of the diluted solutionswith time from the start to the end of the test. Data collectedthroughout this test as exemplified by outputs shown on FIGS. 5, 6 and7, which indicate that the active electrode currents started at anaverage of about 9 milliamps and reduced to an average of 7 milliamps.This was expected as the salinity and therefore the electricconductivity of the solutions in IRCs were reduced. Because the amountof each of the positive and the negative ions corresponding to thetargeted specific gravity reduction were in the order of almost 2200Coulombs, the required time for an average current of 8 milliamps shouldhave been in the order of 153 hours, and not the about 220 hoursexperienced. This increased time is attributed to valve operation delaysthat allowed for reverse ionic currents and some inefficiency of themembranes as used. Despite the above point, the test succeeded intransfer of a total of 4400 Coulombs of total charge to the ion sinksand in major reduction of the salt content of the input solution.

Test 2: The setup for this test was also similar to what is presented onFIG. 1 and test 1, with the difference being that the rubber tube usedwas 9 mm OD. The active electrode IRC was filled with 10% solution ofsilver nitrate and the related ISMs were also attached. The counterelectrode IRC was filled with 3.5% sodium chloride solution.

Given the difference in the mobility of the ions involved, driving ofsilver and chlorine ions was done with active electrode at 5.0 voltswhile sodium and nitrate ions were driven at active electrode voltage of−2.0 Volts. The electric currents were in the order of 100 to 200micro-amps. In this test, within a 50 minute period of the test in whicheach potential was applied for 5 minutes, gradual formation of silverchloride signified by formation of a cloud of precipitates in theappropriate ion sink was clearly observed while the solution in theother ion sink remained completely clear.

The test results presented above reconfirm the basic propositions of thepresent invention, that with use of the process and equipment detailedabove, strong ion currents can be generated, depleting ions from one setof locations and concentrating the separated ions in another set oflocations in a continuous fashion. The entire process is accomplishedwithout electrode reactions. Further, the process of removal andconcentration of ions can be sped up or slowed down at will by simpleadjustments of the applied potentials and speed of valve operations.Further, through the use of this invention, oppositely charged ions fromthe two electrolytes can be directed to two different locations,allowing for the formation of new electrolyte solutions containingoppositely charged ions from each of the original input electrolytes. Asa result, the invention can be used to create chemical compoundscomposed of oppositely charged ions from two differing electrolyticsolutions, or for desalination by removal of ions from a givenelectrolyte such as seawater. The invention can also be used to moveoppositely charged ions of a given electrolyte solution to specificlocations and combine them with hydrogen and hydroxide ions generated bysplitting water to form acids and bases and a variety of other productswithout Redox electrode reactions. Therefore, the present invention canbe used for various industrial processes of choice, including: (1)Manufacturing various chemicals whose constituents are ions or resultfrom ions; (2) Desalination of seawater or brackish water and removal ofhardness from water; and (3) Removal of ionic contamination of anelectrolyte solution.

Test 3: The setup for test 3 was very similar to test 1. In this test itwas intended to cause ion separation and recomposition between a causticsoda and copper sulfate solutions to form sodium sulfate and theprecipitating copper hydroxide.

The active electrode IRC was filled with a nearly saturated solution ofcopper sulfate while the counter electrode IRC was filled with causticsoda solution with a PH of 13.0. Ion sinks were filled with distilledwater. The electrodes used were ¾-inch carbon electrodes described inthe Equipment and Materials section, below. Using the potentiostat powersupply in the chronopotentiometry mode, currents ranging from ±150 microAmps to ±520 micro Amps were imposed in 60 second intervals for 22hours. During this test, positive active electrode potentials (withrespect to reference electrode) ranged from 3.5 to 6.5, while thenegative voltages ranged from −4.0 to −2.5. At this time it was observedthat a very visible precipitate with light blue color indicating theformation of copper hydroxide could be seen in one ion sink as expectedwhile the solution in the other ion sink had clearly remained completelyclear. These observations using a far less sensitive reaction ascompared to reaction of chloride and silver ions reconfirm thecapability of separation and recomposition of ions.

Test 4: For this test, the setup of FIG. 4 and its related operationalprocedure was used. Thus in the second phase, generation of hydrogenions was also accomplished through electrolysis of water, using asulfuric acid electrolyte. Individual IRCs were made up of 1 and 3/16inch OD transparent plastic tubes with the solution height of 170millimeters. The electrode in the sodium chloride solution was agraphite-aerogel electrode with an OD of 10 mm and a length of 12centimeters. The electrodes in the water splitting IRCs were 3/16-inchstainless steel rods (grade 18.8). The Ion Sink containers were ¾-inchin diameter transparent plastic tubing, also with a solution height of170 millimeters and were equipped with electrodes that were electricallyconnected to each other as well as to the reference port of thePotentiostat. Initially the ion sinks were filled with distilled waterwith a measured PH of 7.2. The active IRC contained a 2.7% solution ofsodium chloride while the sodium hydroxide and sulfuric acid IRCSmeasured PH of 11.8 and 2.6 respectively. Each IRC was hydraulicallyconnected to the Ion Sinks using total of 16 centimeters long naturalrubber tubing with OD of 12 mm. The filter holders and pinch valves andtheir control system were as described earlier.

The power supplies used was a Gamry Reference 3000, controlled andoperated through a Sony VAIO laptop computer. In this test thepotentiostat was used in the chronopotentiometry mode in which therequired currents were specified and the device automatically adjustedthe potentials to achieve the required currents. The total duration ofthe test was 370 minutes.

Specified currents ranged from ±100 micro Amps to ±275 micro Ampsapplied in 600 second intervals of positive and 600 seconds of negative.As the test progressed, in each consecutive operation of two cycles ofpositive and two cycles of negative current imposed from the activeelectrode, the currents were gradually increased. An output file fromthis test is presented on FIG. 9 indicating an active electrode positivepotential (with respect to reference electrode) of 3.1 Volts and anegative potential of 7.8 Volts. At the end of test, PH of in ionsolution in the ion sink expected to accumulate positive sodium andnegative hydroxide ions had increased to 10.7 while the PH in the ionsink expected to accumulate positive hydrogen ions and negative chlorineions had dropped to 3.0. PH measurements were carried out using acarefully calibrated EUTECH Instruments pHTestr 10 PH measurementdevice.

FIG. 10 presents an exploded view of one embodiment of the invention, inwhich high porosity carbon electrodes 101 and 102 are connected to theactive poles of a current supply source (not shown) capable ofgenerating electric currents of opposite polarity. These plates are tobe closely positioned adjacent to exchange plates 103 and 104, which aremade up of plastic type materials and have a number of holes asindicated. Each of the holes on plates 103 and 104 are covered by cationexchange membranes 105 or anion exchange membranes 106, as shown. Thereare also blocking plates 107 with holes 108 of similar size as thecation exchange membranes 105 and anion exchange membranes 106. The oneset of holes 108 on plates 107 are positioned such that they perfectlycoincide with either the cation exchange membranes 105 or anion exchangemembranes 106, the remaining holes 108 are completely blocked by thespace between the cation exchange membranes 105 or anion exchangemembranes 106, and vice versa. There are also confined spaces 109 and110 defined by the space between plates 107 and by a divider 111. Thedivider 111 is typically made of metal when the apparatus is powered bya potentiostat and is connected to the reference pole. But if theapparatus is powered by a current or voltage supply source, divider 111should be made from non-conductive materials such as plastics.Typically, the metallic divider 111 is connected to the referenceelectrode of a potentiostat, the first high porosity carbon electrode101 is connected to the active electrode of the potentiostat, the secondhigh porosity carbon electrode 102 is connected to the counter electrodeof the potentiostat. Electric connections are not shown.

The two plates 107 are attached to a mechanical apparatus (not shown)forcing them to move laterally in perfect synchronized movement withpolarity reversals of electrodes 101 and 102. The arrangement shown inFIG. 10 is typically placed in a frame that seals the individualmembranes and electrodes around the edges, preventing flow of ions andliquids from any location but the specified input and output paths. Theapparatus thus described is typically 15 to 100 cm in height and 15 to100 cm wide, with a total assembled thickness of about 10 to 20 mm. Thisassembly with holes of approximately 1.5 cm in diameter can functionboth as a desalination device and for application of ion separation andrecomposition aspects of the present invention.

Another embodiment of this invention is presented in FIGS. 11 a and 11b. FIG. 11 a presents a three dimensional view of a stacked cellarrangement, and FIG. 11 b presents the frontal view of the same cell.Here, all the parts identified with numerals equal to the onesidentified on FIG. 10, refer to the same parts. In addition numerals 112and 113 identify the compartments between each of the high capacityelectrodes and the ion exchange membrane closest to each electrode. Thevalve arrangements 107 and 108 of FIG. 10 are eliminated in the stackedcell arrangement of FIGS. 11 a and 11 b. This stacked cell arrangementcan be used for desalination when the input solution is saline water orcan be used for ion separation and recomposition when the two inputsolutions are different.

In the stacked cell arrangement of FIGS. 11 a and 11 b, sixteencompartments are defined between electrodes 101 and 102, fourteen ofwhich are between ion exchange membranes and two compartments 112 and113 are adjacent to electrodes 101 and 102 respectively. Of the fourteencompartments defined between ion exchange membranes, seven are in thefront row and are totally separated from the seven compartments in theback row by spacer 111 (as shown in FIG. 11 a). The sequence ofmembranes on one side of spacer 111 is indeed a 180 degree horizontalrotation of the sequence on the other side of spacer 111. There are alsoinput and output passages leading in and out of each compartment whichare not shown. These input and output passages are all equipped withcontrol valves (also not shown) that regulate the flow of input andoutput solutions.

In practice, when electrode 101 is negatively charged by connecting itto the negatively charged pole of a direct current electric powersource, (which is not shown) and electrode 102 is connected to thepositive pole of the same direct current electric power source, anelectric field will be invoked that has a direction that is shown at thebottom of FIG. 11 a. Under this condition, one of the seven compartmentsin the back row is then emptied by means of the control valve on itsoutput passage, while all the seven compartments in the front row arefilled with solution. This emptied cell will then create an infiniteelectrical resistance through the back compartments. The establishedelectric field that has been caused by capacitive behavior of electrode101 within compartment 112 and electrode 102 within compartment 113,will cause positively charged ions to flow in the direction of theelectric field and negatively charged ions to flow in the oppositedirection within the front compartments. As positively charged ions areattracted to electrode 101 from the electrolyte within compartment 112,negatively charged ions are correspondingly attracted to electrode 102within compartment 113. Thus, with this mode of operation, the electrode101 and its adjacent compartment 112 and electrode 102 and its adjacentcompartment 113, both act as ion collection cells.

Under this mode of operation positively and negatively charged ions willgradually move out of input compartments 114 and will concentrate in theoutput compartments 110 as positively charged ions are allowed to passthrough cation exchange membranes (see FIG. 11 a) and are prevented toflow through anion exchange membranes (also shown in FIG. 11 a).Correspondingly, negatively charged ions are allowed to pass throughanion exchange membranes and are prevented to flow through cationexchange membranes. As the potential between one or both of electrodes101 and 102 and their adjacent electrolytes reach the level ofinitiating electrode reactions, or at any other convenient time beforethe start of electrode reactions, one of the compartments within theseven front compartments can be emptied to increase the electricalresistance through the front compartments to infinity and thus preventfurther flow of ions through the front compartments. After this phase ofoperation, the polarity of the power supply is reversed, which reversesthe polarity at electrodes 101 and 102. At the same time the empty cellsin the back seven compartments are filled through the input passages.During this phase of polarity reversal, the direction of electric fieldbetween electrodes 101 and 102 will also reverse and will be as shown onthe top of FIG. 11 a. This will lead to flow of positively charged ionstowards electrode 102 and negatively charged ions towards electrode 101and will once again lead to the concentration of ions in outputcompartments 109 and the depletion of ions from input compartments 115both in the back row of compartments. As the potential between one orboth of electrodes 101 and 102 and their adjacent electrolytes onceagain reach the level of initiating electrode reactions or at any otherconvenient time before start of this electrode reactions, the cycle isto be repeated.

Here it is also noted that the number of cation and anion exchangemembrane pairs can be increased to accommodate more cells so long as itis commensurate with the other considerations such as the capability ofthe DC power supply source Further, it is also noted that with thisarrangement, the polarity of charges supplied to electrodes in both thefirst half and the second half of the charging cycle can be reversed. Inthis case the electrodes and their related compartments will now act asIon Repulsion Cells and the location of input and output compartmentswill also switch. This modification can be used to rejuvenate the IonExchange Membranes, if required.

Equipment and Materials

In the tests described herein, the following equipments and materialswere used: The potentiostat used was a Reference 3000 Potentiostatmanufactured by GAMRY Instruments Inc. of Pennsylvania, USA. This devicecan supply up to 3.0 Amperes of current to each electrode and had amaximum active electrode voltage of +/−6.5 Volts. Ion SelectiveMembranes were supplied by Membranes International Inc. of New Jersey,USA. The anion exchange membranes were Model #AMI-7001S and cationexchange membranes were Model #CMI-7000S. Before each use the membraneswere saturated for at least 24 hours in a solution similar to the oneapplied to them in tests. Membrane housings were 37 mm PVC Cassettes(used as inline filter holders) by SKC supplied by Concept Control Inc.of Calgary, Alberta, Canada. Flow cutoff valves were Transport Flowcutoff valves Model 10MM OD 12 VDC NC, Made in Japan, Cole-PalmerCatalogue No. 93305-10. Valve Control circuitry was designed andconstructed by RMT Consultants of Okotoks, Alberta, Canada. This devicewas able to command the valves within a range of 0.1 to 10.0 Volts and−0.1 to −10.0 volts. Plastic Containers used were clear plastic tubingused in aquarium piping. Silver Nitrate, Sodium Chloride, coppersulfate, sodium hydroxide and sulfuric acid used were standard lab gradechemicals from Fisher Scientific. Flexible Tubing was standardlaboratory natural rubber/latex tubing by Fisher Scientific. Titaniumwires used were 1 mm in diameter and were taken from a coarse meshsieve. Specific Gravity measurements were carried out with a CORALIFEDeep Six Hydrometer purchased from Big Al's aquarium store in Calgary,Alberta, Canada.

Two types of carbon electrodes were used. In the first, second and thirdtests electrodes were ⅜ in diameter solid carbon rods, commerciallyavailable under brand name of “Best Weld”. The purchased rods werecopper coated. The copper coating was removed by pealing it off beforeuse. In test 4, the active electrode was a 10 mm in diametergraphite-aerogel composite electrode. These composites were preparedwith the specific intention of allowing for the use ofResorcinol-Formaldehyde aerogels as the dominant phase in order tobenefit from their high surface area, high electric capacitance and lowelectric resistance. Further and in order to avoid the complications andhigh cost associated with supercritical drying usually used to reducethe volume shrinkage associated with drying of such aerogels and aerogelcomposites and in order to further enhance their electric conductivity,graphite powder filler material was incorporated into the mix. Thegraphite powder fill used was laboratory grade #38 commerciallyavailable from Fisher Scientific, Canada.

The typical composition of aerogel base material used was 12.35 grams ofresorcinol and 17.91 grams of 37% methane stabilized Formaldehyde and20.0 grams of water which were mixed and stirred until the Resorcinolwas totally dissolved. Then 1.12 grams of 0.1 Mole solution of sodiumcarbonate was added as catalyst.

The composite was then made using 50% by weight graphite powder detailedabove and 50% aerogel base solution, also described above. The twomaterials were placed in a plastic bag and were extensively mixed byhand for about five minutes. For the purpose of building the rods, thiscomposition was then placed in a transparent plastic pipe and wasextensively tamped to drive out any trapped air.

The resulting components were then sealed using plastic caps and wereallowed to cure for about 24 hours at room temperature followed by 24hours at 50 degrees centigrade and 24 hours at 80 degrees, as iscustomary for RF aerogels. Curing was done while the constructedelements were still in the plastic tubes. In order to prevent distortionand bending of plastic tubes, they were covered by a relatively hardclay paste. Drying and hardening of these clay pastes preventedcurvature and distortion of the plastic tubes and the composite in them.The tubes were then cooled to room temperature. The outer tubes werethen cut open by a rotating blade.

After several hours of further drying at 50 and then 80 degreescentigrade, the components were placed in a refractory mould, coveredwith crushed carbon particles and were heated to 1200 degreescentigrade. This temperature was maintained for about 4 hours. Aftercooling to room temperature, the resulting rods were used.

While the present invention has been illustrated by the description ofembodiments and examples thereof, it is not intended to restrict or inany way limit the scope of the appended claims to such detail.Additional advantages and modifications will be readily apparent tothose skilled in the art. Accordingly, departures may be made from suchdetails without departing from the scope or spirit of the invention.

1. An apparatus for separation and selective recomposition of ions,comprising in combination: a) a first ion repulsion cell through which afirst electrolyte solution can pass, the first ion repulsion cellcomprising an insulated container; b) a first electrode secured insidethe first ion repulsion cell; c) a first pair of flow path means, one ofthe first pair of flow path means hydraulically connecting the first ionrepulsion cell to a first ion sink, the other of the first pair of flowpath means hydraulically connecting the first ion repulsion cell to asecond ion sink, each of the first and second ion sinks comprising aninsulated container made from nonconductive material and having anon-corrosive, metallic reference electrode secured inside, wherein eachof the first pair of flow path means include a flow cutoff valve forselectively opening and closing the flow path means and an ion selectivemembrane for selectively facilitating flow of ions from the first ionrepulsion cell to the ion sinks while preventing the reverse flow ofions from the ion sinks to the first ion repulsion cell; d) a second ionrepulsion cell through which a second electrolyte solution can pass, thesecond ion repulsion cell comprising an insulated container; e) a secondelectrode secured inside the second ion repulsion cell; f) a second pairof flow path means, one of the second pair of flow path meanshydraulically connecting the second ion repulsion cell to the first ionsink, the other of the second pair of flow path means hydraulicallyconnecting the second ion repulsion cell to the second ion sink, whereineach of the second pair of flow path means include a flow cutoff valvefor selectively opening and closing the flow path means and an ionselective membrane for selectively facilitating flow of ions from thesecond ion repulsion cell to the ion sinks while preventing the reverseflow of ions from the ion sinks to the second ion repulsion cell; g) anelectric current supply source for connecting to and controlling thepolarities of the first and second electrodes inside the first andsecond ion repulsion cells, wherein the electric current supply sourceis also connected to the reference electrodes inside the first andsecond ion sinks; and h) a control device connected to the electriccurrent supply source and to each of the flow cutoff valves for sensingthe potential difference between the first and second electrodes andtheir adjacent liquids inside the first and second ion repulsion cellsand then opening or closing the flow cutoff valves to allow ions to flowfrom the ion repulsion cells to the ion sinks.
 2. The apparatus of claim1, wherein the first and second electrodes are high capacity, highsurface area, electrically conductive electrodes, the first electrodebeing an active electrode and the second electrode being a counterelectrode, and wherein the electric current supply source is apotentiostat, the potentiostat operable to utilize the referenceelectrodes in the ion sinks to equalize the currents at the active andcounter electrodes and thus to define the location of the ion sink. 3.The apparatus of claim 2, wherein the electric current supply source isa direct current power source capable of generating electric currents ofopposite polarity, and wherein the direct current power source does notneed to utilize the reference electrodes to equalize the currents at theactive and counter electrodes.
 4. The apparatus of claim 1, wherein theapparatus functions both as a desalination device and as a means for ionseparation and recomposition.
 5. A process for the separation andselective recombination of oppositely charged ions from two differentelectrolyte solutions, the process comprising: a) providing a firstinput electrolyte solution and a second input electrolyte solution ininsulated containers, each input electrolyte solution comprising anequal amount of positive and negative ions; b) generating a positivelycharged ion stream and a negatively charged ion stream from eachelectrolyte solution; and c) selectively combining the positive ionstream from the first input solution with the negative ion stream fromthe second input, and the negative ion stream from the first inputsolution with the positive ion stream from the second input solution, toform new chemical compositions.
 6. The process of claim 5, wherein thepositively charged and negatively charged ion streams are generated byplacing high capacity, high surface area, electrically conductiveelectrodes in each of the first and second electrolyte solutions andapplying an electric current to the electrodes such that two capacitorsin series are formed in each of the first and second electrolytesolutions.
 7. The process of claim 6, wherein the two capacitors in eachof the first and second electrolyte solutions include an inner internalcapacitor and an outer internal capacitor, the inner internal capacitorformed between the electrode and the ions collected on and in closeproximity to the electrode, and the outer internal capacitor formed bythe ions collected on the inner surface of the container and distributedcharges in the outside environment.
 8. The process of claim 5, whereinthe new chemical compositions are formed by causing each of the ionstreams created in the electrolyte solutions to pass out of theirinsulated container, through an ion selective membrane, and into an ionsink.
 9. The process of claim 5, wherein steps (b) and (c) are repeateduntil the extraction of ions from the input electrolyte solutions leadsto a desired level of depletion of ions from each of the electrolytesolutions, or until the collection of new chemicals reaches a desiredconcentration.
 10. The process of claim 5, wherein steps (b) and (c) arerepeated with reverse polarity of electric current applied to eachelectrode, wherein the ion sink acts as an ion source and the ionrepulsion cell acts as an ion collection cell.
 11. The process of claim5, wherein both of the first and second input electrolyte solutions aresea water or brackish water, and wherein the process is used fordesalination of the sea water or brackish water by the removal of bothpositively charged ions and negatively charged ions therefrom.
 12. Theprocess of claim 5, wherein the first input electrolyte solutionincludes hydrogen and hydroxide ions generated by splitting water, andwherein the process is used to move oppositely charged ion streamsgenerated from the second input electrolyte solution to one of the firstand second ion sinks and combine them with hydrogen or hydroxide ionstreams generated from the first electrolyte solution to form newchemicals including acids and bases.
 13. The process of claim 5, whereinthe ion streams are generated in a continuous fashion.
 14. A process forgenerating ion streams, comprising: a) providing a first electrolytesolution and a second electrolyte solution, wherein each solution isplaced in an insulated container and comprises an equal amount ofpositive ions and negative ions; b) separating the positive ions fromthe negative ions in each of the first and second electrolyte solutions;c) electrically drawing the separated ions out of each of the first andsecond solutions as positive and negative ion streams, wherein the ionstreams are generated in a continuous fashion and each of the ionstreams are selectively drawn through an ion selective membrane; and d)pooling each of the ion streams into either a first ion sink or a secondion sink.
 15. The process of claim 14, wherein the separation step (b)is accomplished by placing high capacity, high surface area,electrically conductive electrodes in each of the first and secondelectrolyte solutions and applying an electric current to the electrodessuch that two capacitors in series are formed in each of the first andsecond electrolyte solutions.
 16. The process of claim 15, wherein thetwo capacitors in each of the first and second electrolyte solutionsinclude an inner internal capacitor and an outer internal capacitor, theinner internal capacitor formed between the electrode and the ionscollected on and in close proximity to the electrode, and the outerinternal capacitor formed by the ions collected on the inner surface ofthe container and distributed charges in the outside environment. 17.The process of claim 14, wherein the positive ion stream from the firstsolution and the negative ion stream from the second solution are pooledtogether into the first ion sink, and the negative ion stream from thefirst solution and the positive ion stream from the second solution arepooled together into the second ion sink, allowing for the formation ofnew chemical compounds in each of the ion sinks.
 18. The process ofclaim 14, wherein both of the first or second electrolyte solutions aresea water or brackish water, and wherein the process is used fordesalination of the sea water or brackish water by the removal of bothpositively charged ions and negatively charged ions therefrom.
 19. Theprocess of claim 14, wherein the first electrolyte solution includeshydrogen and hydroxide ions generated by splitting water, and whereinthe process is used to move oppositely charged ion streams generatedfrom the second electrolyte solution to one of the first and second ionsinks and combine them with hydrogen or hydroxide ion streams generatedfrom the first electrolyte solution to form new chemicals includingacids and bases.
 20. The process of claim 14, wherein the process isused for industrial processes selected from the group consisting of: a)manufacturing chemicals whose constituents are ions or result from ions;b) desalination of seawater or brackish water; c) removal of hardnessfrom water; and d) removal of ionic contamination of an electrolytesolution.
 21. An ion separation apparatus for use in separation andselective recomposition of ions, comprising: a) a first high porositycarbon electrode; b) a second high porosity carbon electrode, whereineach of the first and second high porosity carbon electrodes areconnected to opposite active poles of a direct current power sourcecapable of generating electric currents of opposite polarity; c) a firststack of ion selective membranes, the membranes alternating in polarityand having minimum spacing therebetween, the spacing allowing for inputand output passages for supplying electrolyte solutions to compartmentsdefined by the spaces between the membranes, wherein the stack ofmembranes are confined in an electrically insulated container thatprevents any exchange of liquids between the compartments; d) a secondstack of ion selective membranes, the second stack being identical tothe first stack but horizontally rotated by 180 degrees; and e) anelectric current supply source for connecting to and controlling thepolarities of the first and second electrodes.
 22. The apparatus ofclaim 21, wherein the apparatus functions both as a desalination deviceand as a means for ion separation and recomposition.
 23. The apparatusof claim 21, wherein the electric current supply source is a directcurrent power source capable of generating electric currents of oppositepolarity.